[SQL] Related table question

[Eric Forget]

>>           a.RecID not in (select ptr from keyword where name <> 'Me')
>> 
>> 
>> However, I see b) working without understanding it. For me it looks like a
>> double negation. Maybe there is something about SQL I don't understand.
> 
> This is query of kind:
> 
>   WHERE fld IN (v1, v2, v3)
> 
> Here you do not see problems?
> 
> In your query we use subselect to get LIST of values.
> 
>   WHERE fld IN (select ptr FROM T ... )

What I don't understand is why the double negation:

    a.RecID not in (select ptr from keyword where name <> 'Me')
            ^^^                                        ^^

Eric

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 Eric Forget                       Cafederic
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